The premier was hospitalized “as a precaution” at the weekend after his symptoms failed to improve following his positive test for the virus on June 27, his office said on Monday.

Bettel’s blood oxygen levels were low, and his condition was determined as “serious, but stable.”

Doctors will continue monitoring him in hospital for another two to four days, a spokesperson said.

In the meantime, Minister of Finance, Pierre Gramegna, will take over Bettel’s day-to-day affairs, although the PM may still be able to conduct some tasks remotely, his office said.